Cover retainer assembly for inflatable restraint air bag

ABSTRACT

A cover retainer assembly for a support member having a cavity and an air bag disposed within the cavity includes a cover member closing the cavity and having at least first and second edges, a structure for fixedly securing the first edge of the cover member to the support member and a structure for releasably retaining the second edge of the cover member to the support member to allow the cover member to swing open toward the first edge upon deployment of the air bag.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to air bags for vehicles and,more specifically, to a cover retainer assembly for an inflatablerestraint air bag of a vehicle.

2. Description of the Related Art

It is known that vehicles may collide with obstacles during operation.As a result, automotive vehicles have provided various structures tolessen the effects of a collision type impact on an occupant compartmentof the vehicle. For example, some automotive vehicles may include aninflatable restraint air bag to lessen the effects of a collision typeimpact.

It is also known to incorporate an air bag into a steering wheelassembly of a vehicle to lessen the effects of a frontal collision typeimpact on an occupant compartment of the vehicle. For example, thesteering wheel assembly may have a steering wheel cavity, an air bagdisposed in the cavity and a cover member closing the cavity. The covermember is fixedly secured to the steering wheel assembly and may have acentral perforation extending laterally across which tears or separatelytaken the air bag is deployed to allow the air bag to inflate and expandinto the occupant compartment.

While air bags provide an advantage in lessening the effects from acollision type impact, one design constraint is that the material forthe cover member must have a rupture strength satisfactory for coverrelease of the air bag. Also, another design constraint is that thecover member must rupture quickly, thereby allowing high opening forcesfor the air bag upon deployment. A further design constraint is thatattachment hardware and tool assembly are required to assemble the covermember to the steering wheel assembly.

SUMMARY OF THE INVENTION

Accordingly, the present invention is a cover retainer assembly for asupport member having a cavity and an air bag disposed within thecavity. The cover retainer assembly includes a cover member closing thecavity and having at least first and second edges. The cover retainerassembly also includes means for fixedly securing the first edge of thecover member to the support member and means for releasably retainingthe second edge of the cover member to the support member to allow thecover member to swing open toward the first edge upon deployment of theair bag.

One feature of the present invention is that a cover retainer assemblyis provided for an inflatable restraint air bag. Another feature of thepresent invention is that the cover retainer assembly releasably retainsa cover member to a steering wheel assembly. Yet another feature of thepresent invention is that no attachment hardware is required for thecover member. Still another feature of the present invention is thatassembly time for the cover member is reduced. A further feature of thepresent invention is that opening forces for the air bag are minimizedupon deployment of the air bag. A still further feature of the presentinvention is that the rupture strength of the material for the covermember as a factor for satisfactory cover release is minimized.

Other features and advantages of the present invention will be readilyappreciated as the same becomes better understood after reading thesubsequent description taken in light of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevational view of a cover retainer assembly,according to the present invention, illustrated in operationalrelationship to a steering wheel assembly in an occupant compartment ofa vehicle.

FIG. 2 is an exploded perspective view of the cover retainer assemblyand steering wheel assembly of FIG. 1.

FIG. 3 is a fragmentary plan view of the cover retainer assembly andsteering wheel assembly of FIGS. 1 and 2.

FIG. 4 is a partial plan view of a portion of a first alternateembodiment of the cover retainer assembly of FIGS. 1 through 3.

FIG. 5 is a partial perspective view of a portion of a second alternateembodiment of the cover retainer assembly of FIGS. 1 through 3.

FIG. 6 is a partial perspective view of a portion of a third alternateembodiment of the cover retainer assembly of FIGS. 1 through 3 in anunassembled state.

FIG. 7 is a sectional view taken along line 7--7 of FIG. 6 with thecover retainer assembly in an assembled state.

DESCRIPTION OF THE PREFERRED EMBODIMENTS(S)

Turning now to the drawings and in particular to FIGS. 1 and 2 thereof,a cover retainer assembly 10, according to the present invention, isillustrated in operational relationship with a steering wheel assembly,generally indicated at 12, and an occupant compartment 14 of a vehiclesuch as an automotive vehicle (not shown). It should be appreciated thatthe steering wheel assembly 12 is moveable or rotatable and connected tothe remaining structure of the vehicle as is known in the art.

The steering wheel assembly 12 includes a support member or steeringwheel 16 having a central steering wheel cavity 18. The steering wheelcavity 18 is generally rectangular in shape and has an opening facinginto the occupant compartment 14.

Referring to FIGS. 1 through 3, the steering wheel assembly 12 alsoincludes an air bag assembly, generally indicated at 20, disposed withinthe steering wheel cavity 18. The air bag assembly 20 includes areaction member or plate 22 disposed within the steering wheel cavity 18and having a pair of flanges 24 spaced laterally and secured to thesteering wheel 16 by suitable means such as fasteners 26. The reactionplate 22 is made of a metal material although a suitable plasticmaterial may be used. The air bag assembly 20 also includes an air baginflator 28 secured to the reaction plate 22 by suitable means such asfasteners (not shown). The air bag assembly 20 further includes a gas orair bag 30 retained to the reaction plate 22 by suitable means such as ariveted ring (not shown). It should be appreciated that, upon a frontalcollision type impact of the vehicle, the inflator 28 deploys gas intothe air bag 30 to inflate the air bag 30.

The cover retainer assembly 10 controls deployment of the air bag 30.The cover retainer assembly 10 includes a cover member 32 to close theopening of the steering wheel cavity 18. The cover member 32 isgenerally rectangular in shape and has a base portion 34 and sideportions 36 extending from the base portion 34 generally perpendicularthereto. The cover member 32 also has retention straps 38 connected tothe side portions 36 by living hinges 40. The cover member 32 is made ofa suitable material such as a relatively lightweight, soft, thin layerof cloth, vinyl, plastic, leather or a combination thereof.

The cover retainer assembly 10 also includes fasteners 42 such as rivetsfor fixedly securing one of the retention straps 38 to the reactionplate 22. The cover retainer assembly 10 further includes a projection44 extending outwardly from a flange 24 of the reaction plate 22,opposite to the flange 24 to which the retention strap 38 is fixedlysecured. The projection 44 may extend perpendicularly outwardly or at anangle. The projection 44 may also have an end flange (not shown)extending perpendicularly thereto at the free end thereof. The coverretainer assembly 10 also includes an aperture 46 which extends throughthe retention strap 38 to receive the projection 44. It should beappreciated that one of the retention straps 38 is fixedly hinged to thereaction plate 22 and at least an opposed retention strap 38 isreleasably retained to the reaction plate 22. It should also beappreciated that the two other sides of the cover member 32 may haveretention straps 38 releasably retained to the reaction plate 22.

In operation, one of the retention straps 38 is fixedly secured to thereaction plate 22 by the fasteners 42. The opposite retention strap 38is pulled toward the reaction plate 22 to stretch the retention strap 38such that the projection 44 is disposed through the aperture 46. Whenthe inflator 28 is activated, the air bag 30 expands and pressesoutwardly on the cover member 32 until a predetermined force isachieved. At the predetermined force, the projection 44 ruptures andallows the cover member 32 to swing open or rotate toward the fixedlysecured retention strap 38. As a result, the energy of the air bag 30 ismanaged and controlled to minimize the opening force of the air bag 30.Alternatively, the projection 44 may have a generally "V" shaped edge atthe bottom thereof to cut the retention strap 38 as it stretches insteadof rupturing the projection 44.

Referring to FIG. 4, a first alternate embodiment 110 of the coverretainer assembly 10 is shown. Like parts of the cover retainer assembly10 have like reference numerals increased by one hundred (100). Thecover retainer assembly 110 includes the retention strap 138, having aplurality of apertures 146 spaced longitudinally therealong. The coverretainer assembly 110 also includes an inner flange 150 spaced laterallyfrom the retention strap 138 and connected to the side portion 136 bythe living hinge 140. The cover retainer assembly 110 further includes arib 152 disposed in a track 154 between the inner flange 150 and theretention strap 138 for a function to be described. Preferably, aplurality of ribs 152 are spaced along the track 154. The ribs 152 maybe generally circular or rectangular in shape.

In operation of the cover retainer assembly 110, the cover member 132 isdisposed over the opening of the steering wheel cavity 18 such that theflange 24 of the reaction plate 22 is disposed in the track 154 betweenthe inner flange 150 and retention strap 138. One of the retentionstraps 138 is fixedly secured to the reaction plate 22 by the fasteners42. The opposite retention strap 138 is moved toward the reaction plate22 by pushing or compressing the cover member 132 toward the reactionplate 22. When this occurs, the ribs 152 engage the flange 24 until apredetermined force is achieved. At the predetermined force, the ribs152 buckle or collapse to allow the projection 144 to be disposed in oneof the apertures 146. When the inflator 28 is activated the air bag 30expands and presses outwardly on the cover member 132. As this occurs, agenerally V shaped edge 155 on the projection 144 cuts or tears theretention strap 138 and allows the cover member 132 to swing open orrotate toward the fixedly secured retention strap 138.

Referring to FIG. 5, a second alternate embodiment 210 of the coverretainer assembly 10 is shown. Like parts of the cover retainer assembly10 have like reference numerals increased by two hundred (200). Thecover retainer assembly 210 has the retention strap 238 elongated withapertures eliminated. The cover retainer assembly 210 also includes ajaw member 260 molded integral to the reaction plate 22. The jaw member260 has a plurality of teeth 262 spaced longitudinally and extendinglaterally inwardly on opposed sides to form a channel 264 for a functionto be described. The retention strap 238 has a width greater than awidth of the channel 264. It should be appreciated that the teeth 262overlap the retention strap 238 when disposed in the channel 264.

In operation of the cover retainer assembly 210, one of the retentionstraps 238 is fixedly secured to the reaction plate 22 by the fasteners42. The opposite retention strap 238 is pulled toward the jaw member 260to stretch the retention strap 238 and cause the retention strap 238 toneck to a smaller width to fit into the channel 264. The retention strap238 is disposed in the channel 264 and released. This release causes theretention strap 238 to expand and allows a portion of the teeth 262 toengage or bite the retention strap 238 to retain it in place. When theinflator 28 is activated, the air bag 30 expands and presses outwardlyon the cover member 232. The pressure on the cover member 232 causes theretention strap 238 to stretch and neck down to a smaller width anddisengages the teeth 262 to allow the cover member 232 to swing open orrotate toward the fixedly secured retention strap 238.

The retention strap 38, 138, 238 may be molded as an accordion of aflexible material which may be stretched to cooperate with either theprojection 44, 144 or jaw member 260 without making a longer mold. Theretention strap 38, 138, 238 also may be made to different lengths andthe projection 44, 144 or jaw member 260 may be located at variouslocations along the reaction plate 22 to obtain more or less stretch ofthe retention strap 38, 138, 238.

Referring to FIGS. 6 and 7, a third alternate embodiment 310 of thecover retainer assembly 10 is shown. Like parts of the cover retainerassembly 10 have like reference numerals increased by three hundred(300). The cover retainer assembly 310 includes a retention strapretainer 370 connected to the reaction plate 22 by a living hinge 371.The retention strap retainer 370 has a generally rectangular bale 372extending outwardly perpendicularly near the living hinge 371 for afunction to be described. The retention strap retainer 370 also has aflange member 373 extending outwardly and generally perpendicular at afree end thereof. The flange member 373 has a pair of locking tabs 374spaced laterally by a flexible membrane 375 and extending outwardly fora function to be described.

The reaction plate 22 also has a groove 376 extending longitudinally inthe flange 24. The groove 376 is generally rectangular in shape and hasa pair of generally V-shaped recesses 378 extending laterally to receivethe locking tabs 374. The reaction plate 22 also has a pair of laterallyspaced projections 380 extending outwardly on opposed sides of thegroove 376. The projections 380 have generally V-shaped inner edges 382for a function to be described.

The retention strap 338 has a generally rectangular aperture 346extending therethrough. The aperture 346 forms a generally U-shapedstrap for a function to be described.

In operation of the cover retainer assembly 310, the cover member 332 isdisposed adjacent the reaction plate 22. The retention strap retainer370 is rotated or rocked toward the groove 376 by the living hinge 371such that the bale 372 engages an end edge of the aperture 346. Thisengagement moves the cover member 332 toward the reaction plate 22 andpulls the retention strap 338 into tension. The locking tabs 374 engagethe inner edges 382 of the projections 380 and are compressed inwardlyas the membrane 375 flexes to dispose the locking tabs 374 in the groove376. In the groove 376, the locking tabs 374 return to their originalposition such that the locking tabs 374 mate with the recesses 378 toform a snap-fit therein. It should be appreciated that the retentionstrap retainer 370 may be used in place of the fasteners 42. It shouldalso be appreciated that the cover retainer assembly 310 providesserviceability by allowing removal and assembly with simple hand tools.

The present invention has been described in an illustrative manner. Itis to be understood that the terminology which has been used is intendedto be in the nature of words of description rather than of limitation.

Many modifications and variations of the present invention are possiblein light of the above teachings. Therefore, within the scope of theappended claims, the present invention may be practiced other than asspecifically described.

What is claimed is:
 1. A cover retainer assembly for a support memberhaving a cavity and an air bag disposed within the cavity comprising:acover member closing the cavity and having at least first and secondedges; means for fixedly securing said first edge of said cover memberto the support member; means for releasably retaining said second edgeof said cover member to the support member to allow said cover member toswing open toward said first edge upon deployment of the air bag; areaction member disposed within the cavity and secured to the supportmember; and said releasably retaining means comprising a jaw memberattached to said reaction member and having a plurality of teeth spacedlongitudinally and extending laterally inwardly on opposed sides to forma channel, said second edge being disposed longitudinally in saidchannel.
 2. A cover retainer assembly for a support member having acavity and an air bag disposed within the cavity comprising:a covermember closing the cavity and having at least first and second edges;means for fixedly securing said first edge of said cover member to thesupport member; means for releasably retaining said second edge of saidcover member to the support member to allow said cover member to swingopen toward said first edge upon deployment of the air bag; said covermember having a base portion and side portions extending from said baseportion, said first and second edges being retention straps hingedlyconnected to said side portions; and said retention straps being formedas corrugated straps which may be stretched to a linear shape.
 3. Acover retainer assembly comprising:a support member having a cavity; areaction member disposed within said cavity and secured to said supportmember; an air bag disposed within said cavity and operatively connectedto said reaction member; a cover member closing said cavity and havingopposed first and second edges; means for fixedly securing said firstedge of said cover member to said reaction member; and a jaw memberattached to said reaction member and having a plurality of teeth spacedlongitudinally and extending laterally inwardly on opposed sides to formchannel, said second edge being disposed longitudinally in said channelfor releasably retaining said second edge of said cover member to saidreaction member to allow said cover member to swing open toward saidfirst edge upon deployment of said air bag.
 4. A cover retainer assemblyas set forth in claim 3 wherein said cover member has a base portion andside portions extending from said base portion, said first and secondedges being retention straps hingedly connected to said side portions.